gp chi Khoa hoc - Cong nghe Thuy sdn
THONG B A O KHOA HOC
CHE TAO THU* NGHIEM MOI HAN MA SAT HOHP KIM NHOM 6061 TREN MAY PHAY TAI TRlTOfNG DAI HOC NHA TRANG
EXPERIMENTAL FABRICATION OF AA6061 FRICTION STIR WELDING BY THE MILLING MACHINE AT NHA TRANG UNIVERSITY
Tran Himg Trd\ Phi Cong Thuyen' Ngay nhan bai: 17/3/2013; Ngay phan bien thong qua: 27/5/2013; Ngay duyet dang: 10/12/2013
rOM TAT
Moi hdn ma sdt giira hai tdm hgp kim nhom 6061 duac che tgo thu nghiem a nhieu che do hdn khdc nhau du&i su
•et hpp giOa tdc do hdn, toe do quay chot hdn, vd hinh dang chdt hdn Anh hu&ng cua cdc thong so hdn ndy den dQ ben keo loi hdn dupc khdo sdt sau khi che tao thdnh cong. Ket qud nghien cuu cho thdy muc dQ thdnh cdng trong che tqo moi hdn
\pp Idm nhom 6061 bf giai hgn rdt ldn bdi hinh dgng chot hdn, toe do quay vd toe dd Unh tien chot hdn, cong sudt vd do m dfnh cua mdy Trong so cdc moi hdn dupc che tgo thdnh cong, dp ben mdi hdn tdng khi gidm ti le giUa toe dp quay chdt tdn vd toe dp hdn tdng len. Moi hdn bi khuyet tdt nghiem trong do thieu khuech tdn vgt li^ khi che tgo a ti 14 giira tdc do may chdt hdn vd toe dp hdn qud thdp
Tic khda: hdn ma sdt. hpp kim nhdm 6061, ca dnh ABSTRACT
The stir friction welded-joint of aluminum alloy 6061 is fabricated at vanous conditions under the combination
\mong weld speed, pin rotation speed, and pin geometry. The affect of these welding parameters on the tensile strength of he joint IS investigated The experimental result shows that the fabricability of the friction joints is affected significantly (V the pin geometry, pin rotation, weld speed, machine power, and machine stability. In the joints successfully fabricated, he tensile strength of the joint is increased with the reduction ofthe ratio of pin rotation speed and welding speed At quite ow value ofthe ratio of pin rotation speed and weld speed, the joint is incomplete concerning to the lack of metal diffusion
Keywords Friction stir welding, aluminum alloy 6061, tensile properties
. D A T V A N D ^ khd tinh nhit khdng t h i han bing ky thuat hdn Hdn ma sdt la phuang phdp han khd mdi. mdi chdy taiyln thdng [2]. Do mdi hdn dugc hinh thanh ldn dugc tgo ra do ddng v|t lieu khulch tdn giOa trong qua ti'inh biln dgng ea nhidt tuong tac nen iai t i m hdn nhd vdo qud trinh ca nhidt sinh ra bdi cau true vd ea tfnh tgi khu vue hdn r i t phdc tap. bj na sdt [1]. Bdn chit ciia qua trinh hinh thanh ta anh hudng bdi nhieu y l u td trong qud trinh hdn nhu jud trinh ca nhigt tuang tdc vd mdi hdn dugc hinh hinh dang chdt han. hg thdng dd gd. tdc dd quay hdnh d nhigt dg dudi nhidt dp chdy vdt lidu. Day ctia chdt hdn. tdc dg hdn, do dn djnh eOa mdy han...
\ phuang phdp hdn duge xem Id uu vigt nhd kha Hidn tgi, hdn ma sdt dang 6ugc nghien cdu va ung ldng hdn hau het d c hgp kim ke d d c hgp kim dyng r i t mgnh d nhilu nude, tuy nhien cdng nghe
TS Trin Hung Tr^ Khoa XSy dung - Tnrdng Ogi hgc Nha Trang
ON, Phi Cdng Thuyfin: Trung tdm Thi nghi§m thi/c hdnh - Tnrdng Dgi hpe Nha Trang
TRUONG OAI HOC NHA TRANG • 45
Tap chi Khoa hoc - Cong nghe ThOy san S6 4/20n
ndy cbn khd xa Igi d trong nude do thieu thdn tiBogtiiiet bj. Vdi nhung uu diem vugt tid' ctia cdng nghd hdn ma sat. vigc d g m til img dyng d n g nghe nay td mdt sg phung phi vd d n g til tdn Nhdm budc dau nghien d u ehe tao mdi hdn ma sdt ti^en ca sd tdn dung nhirng thilt bj hien d tgi tnrdng. nhdm chiing tdi mgnh dgn thue hien nghien cuu c h l tgo thip nghigm mdi hdn ma sat cho hgp kim nhdm 6061 tidn ea sd sir dyng may phay dung tgi Xudng Ca khf, Tnrtmg Ogi hpe Nha Trang. Nhung kit qua nghidn ctru thdnh d n g birdc diu se dugc d n g bo trong bai bdo ndy Su anh hudng eua tdc dp hdn vd tdc dg quay chdt han din ca tfnh ctia d c mdi hdn dugc ehe tao thdnh cdng dugc d l dP- 11. D6t TirqrNG, VAT u e u VA PHU'ONG P H A P NGHIEN COU
Hgp kim nhdm tam 6061 ddy Smm duac tiln hdnh hdn gidp m( bing cdng nghg ma sat tren mdy phay dirng tgi xudng Ca khi Trudng Dgi hgc Nha Trang. Thanh phin hda hgc cua t i m hgp kim nhdm 6061 ti'inh bdy trong bang 1. Mdi hdn duge chl tgo tren mdy phay dung UF222, cdng suit lOkW, cimg
vdi cum dd gd nhu trong hinh 1. Thilt bj dd gig c6 nhiem vy giu d hai tam han nim phang, khflng h djch chuyin bong mat phang vudng gdc vdi c*i4t han. Phuang phdp nghien ctru dugc tilp can theo con dudng thgc nghigm tix)ng dd dga vdo c:6ng sub may vd ca ttnh ciia vgt tigu hdn de ehon tya ctie dp hdn. Mdi hdn dugc ehe tgo trong dilu kign moi tiirdng thudng, khdng gia nhigt, trong dd tiiuc hien nhieu t^e dd han tiang sg k i t hgp d a hinh dang chdt hdn, tdc dp quay chdt hdn, va tde dp tinh tien chdt han. Qua trinh c h l tao thu nghiem tiem cjn dan d i n kit qua dua tren chit tugng khuech tan v§t lidu tgi viing han. Mdi hdn dugc xem td chet^
thdnh edng khi quan sdt ti'dn kinh hiln vi khong phai hien khuylt tdt tren mgt d t ngang mdi han Trong bai bao ndy se de cap den nhung sd tigu da di tgo mdi hdn thdnh cdng. Hinh dgng chdt hdn dung ehe tgo mdi hdn dugc t h i hidn trong hinh 2. C^
mdi han dugc d l tgo thdnh d n g d edc chl dp \\in dudi su k i t hgp gitra tde dp hdn (ky hieu v) vd lie dp quay chdt han (ky hieu to). Ca ti'nh mdi han 6\ifjz do bang mdy do ea tinh INSTRON 3300.
H ^ Mm nhAm 6061
AI 98.8
Bang 1. Thdnh phan hda h9C cua h9^ kim nhom 6061 [3]
Mg 0,8-1,2
Si 0,40- 0,80
Fe 0,30
Mn 0,10
Zn 0,25
Cu 0,50- 0,30
Cr 0,50- 0,30
Tl 0,15
Tfpdiil ConM
III. K^T QUA NGHIEN CLTU VA T H A O L U A N Nhilu mdi hdn dugc c h l tgo vdi cac loai chdt hdn khdc nhau kit hgp vdi thay ddi tdc do quay chdt hdn vd tdc dp tinh tien chdt hdn, phin tdn mdi hdn duge chl tgo vdi chat tugng thip do thieu khulch tan vat lidu giua hai tam hdn. Mdt sd mau dugc che tgo thdnh cdng, diln hinh xem hinh 3.
Trong nghidn cuu ndy mdi han hgp kim nhdm 6061 duac c h l tgo thanh cdng d ba c h l do kit hgp sau: ti le giua tdc dd quay vd tde dp tjnh tiln chdt hdn Id 12 vdng/mm, 19,2 vdng/mm, vd 45,4 vdng/mm.
Dp ben keo eiia mdi han duge do bdi may keo vgn nang INSTRON 3300 vdi tdc dp biln dang lO^/s vdi mau dugc md ta ti'ong hinh 4 tiieo tieu chuan ASTM E647 Kit qua do ca tinh gdm dd ben keo va do gian ddi dugc till hidn trong hinh 5 vd 6. Moi gia tli Id
46 • TRUONG DAI HOC NHA TRANG
gia tri tiung binh cua hai m l u thi nghiem d ciing chi dp ban. K i t qud thi nghidm cho thay, d tat d ch4 fl) hdn, dp bin mdi han deu thip han do ben vgt lifu nIn. Nhin ehung, dp bin kdo mdi hdn nim trong khoang 60% den 80% dd bin kdo vat tidu nen vS S>
gidn ddi mdi han ndm trong khodng 45% din 60% so vdi vat lieu nen. Anh hudng cua tdc dp quay vd tic dd tinh tien chdt hdn den dg tien kdo dugc thi ii^
trong hinh 5. Dd bin keo bj gidm khi tang fi l§ o'*' dieu nay lien quan den vigc tdng nhigt dfl tgi vting han khi tdng ti Id o/v [3-6]. Do hgp kim nhfim 6061 la hgp kim dugc tang ben bing phuang phdp ffwi trj nhiet tgo pha k i t tinh (precipitates hardening), vi vgy khi nhigt do han tang cao se lam tdng MB nang tan cdc hgt tang b i n (precipitates) va Idm gii"
dd ben tai viing han.
rap chi Khoa hoc - Cong nghe Thuy sdn So 4/2013
Hinh 3. M6i h i n ma silt diT9'c che tao Trdn phuang di$n ty thuylt phdn tfch nhigt rong mdi hdn [4-7] thi md men quay chdt hdn se can bang vdi md men do Igc ma sdt sinh ra rdn b l mdt tilp xiic giua chdt hdn vd t i m hdn
W R R
M= fciW =j//p(r)2w^(/r , trong dd Mid md
0 0
nen quay chdt hdn, p Id hd sd ma sdt giira chdt han /di t i m hdn, p(r) Id dp Igc phan bd tren b l mgt tilp (UC, R td ban kfnh vai chdt ban. Nlu toan bd cdng ma idt trdn b l mdt tilp xtic chuyen thdnh nhigt ma sdt
hi ta ed thi viet q = \ oxiM = J o)f^{r)2nr-dr.
rong dd o td toe dd quay chdt hdn Nhigt dp tai vung ldn se ti tg nghjch vdi tde dd hdn, n l u tdc dd hdn di :huyln d n g nhanh thi nhigt tgp tmng cdng thap vd iguge tgi Tir ca sd ly thuylt ndy ehung ta ed t h i / gidi cho vide tang nhidt dp hdn khi tdng ti Ig a/v.
Ngodi uu dilm tang dd ben mdi ndi bdng each
|iam ti Ig m/v thi vi$c gidm ti Id 6)/v cdn cd ^ nghTa
|idm ndng tugng hdn trdn mgt dan v| chilu ddi ludng hdn. Ddy td mdt trong nhtrng dilm uu vigt tia hdn ma sdt cho hgp kim 6061. Tren ca sd dtr du tiong hinh 5 eho phdp ta chgn c h l dd hdn hgp ) de dgt dg b i n mdi hdn cao nhit. Cung d n chti y Ing, khi gidm gid tri ti Id cVf xudng qud tiilp sd ldm
Ifinh 2. Hinh dang hinh hoc chot han
Hinh 4. Mau do dg b i n keo
mdi hdn bi khuyet tdt do thilu kha nang khuech tan bdi nhiet do hdn qua thip.
"ni^ gi&a tica$ quay vA t6c a*tjnh li4n, viing/mm H m h 5. Quan h^ giua do b i n keo vol ti 1^ giun t6c dg quay
chot han va toe d6 hka (oi/v) Buprig nel dut la gia Itj cua \al lieu nen
nif^glOatdc dp quay v d t 6c detinh fiSn.vong/mm
Hinh 6. Q u a n h^ gi&a dS giau dai vol ti le giira toe dp quay chot ban v i toe dg han (lo/v) Duung nel dut la gta irj am vdt It^ nen
TRUONG OAI HOC NHA TRANG • 47
Tap chi Khoa hoc - Cong nghe Thuy sdn So 4m
IV. K^T LUAN VA KI^N NGHj
K i t qud nghien cuu cho thay mdi hdn ma sdt hgp kim AA6061 dugc c h l tgo thdnh edng d cAc c h i do hdn khdc nhau vd dd ben kdo cua nd bj dnh hudng kha ddng ke bdi ca tde dp hdn va tdc dg quay chdt hdn. Dp ben keo mdi hdn thay ddi tuyen tinh vdi tl Ig gida tde dd quay chdt han va tde do ban w/v. Dg ben mdi ban tdng ten khi giam ti tg (i)/v, tuy nhidn viec giam ti ig to/v din mdt gidi hgn qud thap Idm giam su dn dinh cua may hdn vd mdi hdn khdng the hinh thdnh. Nghidn edu da dgt duge nhung kit qua rat khd quan khi tan dyng
may phay hidn d d l c h l tao mdi hdn ma sat ttl|t dil da c h l tgo thdnh cdng mdi han ma sdt song^
qua tir nghien cuu ndy chua the d l xuat thdngsj han tdi uu cho hgp kim nhdm 6061 do sg hgn die cua cdng suat vd tinh dn djnh cOa thilt bj. Tacgjj bdi bdo ndy kien nghj tilp tyc phdt triln nghien ahi hdn ma sdt cho hgp kim nhdm trdn thiet bj hanci cdng suat Idn han, phgm vi thay ddi tde dp i^
han, mdy cirng vtrng vd dn djnh han de cd Uiexac djnh chfnh xac muc dd dnh hudng cda cac th6ng sd han d i n chat lugng mdi hdn ctJng nhu xac dinh che dg hdn tdi uu.
TAI LIEU THAM KHAO
1 Frigaard 0., Grong 0., Midling O.T., 2001 A process model for fiiction stir welding of age hardening alumtnum alloyi.
Metallurgical and Materials Transactions A Physical Metallurgy and Materials Science, 32(5). 1189-1200.
2 Fu Z -H., He D -Q., Wang. H , 2004. Fnction stu' welding of alummum alloys Journal Wuhan University of Technoloiy, Materials Science Edition, 19(1): 61-64.
3 Midling O.T., Cjrong 0., 1994. A process model for diction welding of AIMgSi alloys and AlSiC metal matrix cotnpositesL Haz temperature and strain rate distnbution. Acta Metallurgica Et Malenatia, 42(5): 1595-1609.
4 Midtmg O T, Grong 0., 1994 A process model for friction welding of AIMgSi alloys and AlSiC metal matrix coniposit»-Il Haz nucrostructure and strength evolution Acta Metallurgica Et Malenalia, 42(5): 1611-1622.
5 Mishra R.S, Mahoney M.W., 2007. Fnction Stir Weldmg and Processing. Ohio 44073-0002 ASM InlemaDonaK Materials Park.
6 Mishra R.S.. Ma Z.Y, 2005. Friction stir welding and processing Matenals Science and Engmeenng R, 50:1-78.
7 http://wwwshaliimi.com.vn/index.php/dnews/238/Tlianh-phan-hoa-hoc-cua-hop-kim-nhoni.htmf.
48 • TRUCfNG OAI HOC NHA TRANG
